VSAT proves crucial to battlefield communications

Very-small-aperture terminal technology has proven to be an indispensable tool for command and control because it allows real-time voice, video and data transmission without communications infrastructure or line-of-sight positioning for fixed and on-the-move applications.

VSATs, which are small satellite dishes, have proven to be lifesavers in battle zones, particularly for logisticians who can use the technology to transmit information rather than having to join a convoy to carry and deliver a re-supply order in person.

“In a war zone, a soldier who needs to order parts would typically have to get into his vehicle and drive from one outlying camp to another,” said Paul Brown, technical adviser for VSATs at Project Manager, Defense Communications and Army Transmission Systems (PM DCATS), at Fort Monmouth, N.J. “Providing them with a VSAT solution allows them to stay within the wire of their base and communicate directly to order those parts. VSATs save lives; that’s the critical piece.”

More than 1,000 VSATs that support combat operations have already been delivered to the field under the Connect Army Logisticians program, and there is a potential for 2,000 more orders, according to PM DCATS.

L-3 Global Communications Solutions manufactures the CSS VSATs and is supplying the program with 20 to 25 of its 1.2-meter Hawkeye VSATs every week, said Bob Jacobson, executive vice president and general manager of L-3 GCS. The company has reduced the dish size of the Hawkeye technology to 0.9 meters for use by the Special Operations Command in Afghanistan, he added.

The Army is acquiring thousands more VSATs under the five-year, $5 billion World-Wide Satellite Systems contract, under which Army personnel can buy VSATs from six approved vendors. In one of the largest procurements, the Army Communications-Electronics Life Cycle Management Command is buying VSAT systems to send encrypted voice, video and imagery data. TeleCommunication Systems is supplying the VSATs under a $246 million contract that includes options for about 1,500 systems. The company is delivering eight systems per week, said Mike Bristol, senior vice president of the company’s Government Solutions Group.

With VSATs flooding into Iraq and Afghanistan, lessons learned are plentiful. For example, VSAT users need to understand the proper function of technologies such as auto pointing, which automatically syncs a VSAT to a satellite.

“You pay a cost to get auto-point capability,” Brown said. “If an antenna is on top of Wal-Mart or Home Depot and is never going to move, why would you pay for a technology that you’re never going to use? It’s the same on the military side. If I’m supporting a hospital that’s never going to move, why spend the extra money? So you put a fixed antenna there.”

Another lesson addresses satellite bandwidth and the need for new technology that makes existing bandwidth go further.

“There is no bandwidth available over [Southwest Asia] right now, so you just can’t give everybody a satellite dish,” Brown said. “They also have to understand that it’s expensive to buy satellite bandwidth, so it is important to pool all these users together to share the cost of bandwidth.”

PM DCATS is working to solve that problem through development of an IP modem that lets multiple users share a pool of satellite bandwidth. The modem, which the military is developing with ViaSat, incorporates the DVB-S2 waveform, which the company said offers as much as 30 percent greater bandwidth efficiency.

Man-portable VSATs

The next evolutionary step in military VSATs is miniaturization, which will allow warfighters to transport all the hardware in a single rucksack. The Special Operations Command is interested in man-portable VSAT systems and expects to issue a request for proposals by early fall under the Special Operations Forces Deployable Node-Lite (SDN-L) program.

Miniaturization is a challenge that will stretch the capabilities of VSAT providers, experts say.

“You have to have an end-to-end understanding of VSATs — not just the dish but all satellite-managed services,” said Jim Sprungle, vice president of government programs at TeleCommunication Systems. “You have to understand routing, satellite acceleration because of latency and information assurance, and then put it all together in a small package, cool it and make sure it works after bouncing around in a Humvee.”

SDN-L would allow tactically deployed users worldwide to connect to the Special Operations Forces Information Enterprise, according to the statement of work for the latest version of the program. As many as four laptop PC users would be able to access services at multiple classification levels.

The satellite communications terminal will be configured with an Inmarsat Broadband Global Area Network (BGAN) terminal or a Ku-band terminal that incorporates technology from iDirect. In the production qualification phase, the competing contractors will each provide five BGAN and five Ku-band systems for testing and integration. All variants of the satcom modem must support a minimum data rate of 350 kilobits/sec.

Jacobson said L-3 GCS has already developed a VSAT called Panther that can deliver 1 megabit/sec of data and is selling them to the military in advance of the SDN-L program.

The goal is to transport the SDN-L system in a rugged transit case to the area of operations via military or commercial aircraft. When in operational mode, users would remove the laptop PC and satcom terminal from the chassis and carry them in their backpacks.

Prototype units, excluding the auxiliary battery case, cannot exceed 55 pounds, with the final objective being 45 pounds. Threshold weight for the satcom, laptop PC and High Assurance IP Encryptor functions cannot exceed 17 pounds, with the final objective being less than 17 pounds, not including the case, battery backup, and ancillary or auxiliary items.

Those figures are for the BGAN system. A maximum of 15 pounds can be added to each system weight parameter for the Ku-band configuration.

Army officials agree that the greatest engineering challenge in accomplishing the goals of SDN-L will be development of an internal, rechargeable battery.

“The challenge with developing simple, lightweight terminals is, as with any tactical unit, power,” Brown said. “The technology is there to make a small satellite terminal, but how do I make it so that it’s lightweight and also includes the necessary power? If two people are hoofing it through the woods, how do I get them to power this thing when they get to where they’re going?”

The Special Operations Command has specified that the system’s battery must use dry-cell technology that has been approved for air and surface transportation and provide backup power with a minimum life of 30 minutes at maximum current draw or 1.5 hours to support powering the internal components of the baseband chassis, which doesn’t include powering the laptop PC.